The disclosures herein relate generally to a computer system and more particularly to an EMI seal for a computer system chassis.
Increasing processor speeds are requiring improved electromagnetic interference (EMI) containment by a metal enclosure. The inability of individual metal fingers to be manufactured on a spacing that would be effective at the higher frequencies requires a continuous gasket.
Prior methods used to contain emissions include metal fingers made of various materials. The metal fingers can only be produced at large incremental spacing preventing the enclosure from providing a continuous EMI seal. Other methods are to use a tongue and groove concept to provide a labyrinth wave-guide to contain the emissions. The issue with these types of seals is intermittent contact at the seams. This creates larger problems than having no contact at all.
An EMI gasket has been used in various applications over the past few years. The gasket is typically applied using an adhesive. Adhesive adds cost and does not protect the gasket from abuse. The gasket adhesive is typically non-conductive which negatively affects the total surface area for gasket to metal chassis contact. Other applications require multiple parts to protect the gasket from customer abuse.
Therefore, what is needed is a chassis which limits the number of parts, creates a seal using a gasket and limits exposure to sharp edges.
One embodiment, accordingly, provides a chassis seal which includes a gasket that does not require an adhesive. To this end, a computer chassis includes a metal chassis base portion and a metal chassis top portion. A pivotal connection is provided between the top portion and the base portion for movement of the top portion between an open position and a closed position with the base portion. A tongue and groove edge connection extends between the top portion and the base portion. An adhesive free gasket is mounted in the groove for sealing engagement with the tongue.
A principal advantage of this embodiment is that the gasket seal enhances EMI containment within the metal chassis.